Systems and methods for limb alignment
The present invention provides, in certain embodiments, a device for determining the tibial mechanical axis and the femoral mechanical axis. The present invention also provides a surgical orientation device, a reference device, and/or a module configured to track the mechanical axes during movement to facilitate limb alignment. The present invention further provides the surgical orientation device, the reference device, and/or the module configured to determine a gap measurement.
1 . A system for limb alignment, comprising:
a first orientation device configured to be coupled with a tibia before resection, the first orientation device comprising at least one inertial sensor to assess characteristics of a knee joint before resection;
a second orientation device configured to be coupled with a femur before resection, the second orientation device comprising at least one inertial sensor to assess characteristics of the knee joint before resection; and
a femoral preparation system comprising a bone engagement portion configured to be driven into the femur and a coupler portion, wherein the second orientation device comprises an interface configured to be lowered onto the coupler portion to mount the second orientation device directly to the coupler portion, wherein the femoral preparation system is configured to be mounted to the femur, outside of the space between the tibia and the femur to allow the knee to articulate along natural articular surfaces of the tibia and the femur and be placed in flexion and extension before resection,
wherein the first orientation device or the second orientation device comprise a processor configured to receive inertial sensor data, wherein the processor is configured to determine a femoral mechanical axis and a tibial mechanical axis in flexion, wherein the system for limb alignment is configured to store a relative positioning of the femoral mechanical axis and the tibial mechanical axis before resection, wherein the processor is configured to calculate an angle between the femoral mechanical axis and the tibial mechanical axis when the first orientation device is coupled with the tibia before resection and the second orientation device is coupled with the femur before resection.
2 . The system of claim 1 , further comprising a tibial preparation system comprising a first device interface configured to couple to the first orientation device and a second device interface configured to couple to the second orientation device.
3 . The system of claim 2 , wherein the femoral preparation system is configured to be mounted on the tibial preparation system.
4 . The system of claim 1 , wherein the femoral preparation system comprises a cutting guide bracket configured to slide relative to a tibial preparation system.
5 . The system of claim 1 , wherein the femoral preparation system comprises a swivel post configured to swivel relative to a tibial preparation system.
6 . The system of claim 1 , wherein the femoral preparation system comprises an extension configured to be positioned relative to a threaded pin coupled to a portion of the distal femur.
7 . The system of claim 1 , wherein the processor is configured to determine the femoral mechanical axis and the tibial mechanical axis based at least in part on the location of anatomical landmarks.
8 . The system of claim 1 , wherein the processor is configured to determine the femoral mechanical axis and the tibial mechanical axis based at least in part on movement of the femur.
9 . The system of claim 1 , wherein the processor is configured to determine varus/valgus angle of the femoral mechanical axis and the tibial mechanical axis.
10 . The system of claim 1 , wherein the processor is configured to determine flexion/extension angle of the femoral mechanical axis and the tibial mechanical axis.
11 . The system of claim 1 , wherein the processor is configured to determine a gap measurement.
12 . The system of claim 1 , further comprising a tibial preparation system comprising a probe member.
13 . The system of claim 1 , further comprising a tibial preparation system comprising a midline reference probe assembly.
14 . The system of claim 1 , wherein the first orientation device and the second orientation device are configured to determine alignment of the femoral mechanical axis and the tibial mechanical axis before and after resection.
15 . The system of claim 1 , wherein the first orientation device and second orientation device are configured to sense changes in orientation, wherein changes in orientation when the leg is in flexion and when the leg is in extension determine the angulation of the femoral mechanical axis and the tibial mechanical axis.
16 . The system of claim 1 , wherein the first orientation device and second orientation device are configured to verify the femoral mechanical axis and the tibial mechanical axis after resection.
17 . The system of claim 1 , wherein the first orientation device and the second orientation device are configured to calculate a rotation of the tibial mechanical axis about the femoral mechanical axis when the first orientation device is coupled with the tibia before resection and the second orientation device is coupled with the femur before resection.
18 . The system of claim 1 , wherein changes of the femoral mechanical axis and the tibial mechanical axis are measured in the coronal plane.
19 . The system of claim 1 , wherein changes of the femoral mechanical axis and the tibial mechanical axis are measured in the sagittal plane.